dm target:s introduce iterate devices fn

Add .iterate_devices to 'struct target_type' to allow a function to be
called for all devices in a DM target.  Implemented it for all targets
except those in dm-snap.c (origin and snapshot).

(The raid1 version number jumps to 1.12 because we originally reserved
1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors'
instead.)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: martin.petersen@oracle.com

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 04db6c4004a8..9933eb861c71 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1313,9 +1313,17 @@ static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
         return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
 }
 
+static int crypt_iterate_devices(struct dm_target *ti,
+                                 iterate_devices_callout_fn fn, void *data)
+{
+        struct crypt_config *cc = ti->private;
+
+        return fn(ti, cc->dev, cc->start, data);
+}
+
 static struct target_type crypt_target = {
         .name   = "crypt",
-        .version= {1, 6, 0},
+        .version = {1, 7, 0},
         .module = THIS_MODULE,
         .ctr    = crypt_ctr,
         .dtr    = crypt_dtr,
@@ -1326,6 +1334,7 @@ static struct target_type crypt_target = {
         .resume = crypt_resume,
         .message = crypt_message,
         .merge  = crypt_merge,
+        .iterate_devices = crypt_iterate_devices,
 };
 
 static int __init dm_crypt_init(void)